Parents put on alert after deadly enterovirus linked to child's death in NSW

The New South Wales Health Department is urging parents to be on the lookout for symptoms of a rare virus that has been linked to the death of a child.

The child was also suffering other infections, and doctors have not confirmed if enterovirus 71 (EV71) caused the death.

Three other young children's deaths in the past six months, including one in the Hunter region, have been linked to EV71.

The Health Department says it cannot reveal where the fourth child is from.

General enterovirus is common in Australia, and often causes hand, foot and mouth disease in children.

The NSW Director of Communicable Diseases, Vicky Sheppeard, says the fatal strain has killed otherwise healthy children, and has different symptoms to general enterovirus.

"The signs of the severe illness are a high fever, children could be quite lethargic or quite irritable, they might show unsteady walking or [appear] off-balance or they might have jerky movements of the limbs," she said.